摘要： 采用种子乳液聚合法,通过引入功能单体甲基丙烯酸乙酰乙酰氧基乙酯(AAEM),并按酰肼基团与乙酰乙酰基团不同物质的量比添加交联剂碳酸二酰肼(CAH),合成了可室温自交联的丙烯酸酯乳液(ACMA)。通过测定不同温度下的转化率,确定了ACMA聚合的最佳温度为80℃。探讨了不同酰肼基团与乙酰乙酰基团物质的量比对胶膜交联度、耐水性、接触角、力学性能、热稳定性的影响。结果表明:当酰肼基团与乙酰乙酰基团物质的量比为1∶1时,ACMA胶膜的交联度为95.78%,吸水率降至12.4%,接触角达到94.7°,拉伸强度升至7.3 MPa,同时热稳定性提高。将ACMA乳液配制成水性清漆,随着酰肼基团与乙酰乙酰基团物质的量比的增加,铅笔硬度提高,附着力较好。

关键词: 交联改性, 乙酰乙酰基团, 丙烯酸酯, 碳酸二酰肼, 力学性能, 热稳定性

Abstract: A room temperature self-crosslinkable polyacrylate (ACMA)emulsion was prepared by using acetoacetoxyethyl methacrylate(AAEM)as functional monomer through the seed emulsion polymerization, wherein the carbohydrazide(CAH)as crosslinker with different molar ratio of n(-NH2 -) therein to n(-CO-CH -co-)in AAEM was added. The optimum reaction temperature 80 C was obtained by testing the conversion rate at different temperature. Effects of the molar ratio of n(-NH2 - ) n(-c0-ch-c0-)on the gel content, water-resistance, contact angle, mechanical properties and thermal properties of the film were evaluated by using the gel content, water absorption, contact angle analyzer, mechanical testing machine and thermo gravimetric analysis. The results showed that when the molar ratio of n(-NH,-): n(-CO-CH - Co-)was 1: 1, the gel content increased to 95.78% water absorption decreased to 12.4%, contact angle was up to 94.7, tensile strength increased to 7. 3 Mpa, and the thermal stability enhanced. The waterbome varnish was prepared y using the ACMA emulsions. With the increment of n(-NH,-)n(-CO-CH2-CO-), the pencil hardness increased and the adhesion was good.

Key words: crosslink-modified, acetoaceto groups, polyacrylate, carbohydrazide: mechanical properties, thermal stability